Time stamps can be used to associate a time with an event. A time stamp can reflect the actual time or can reflect an elapsed time relative to an arbitrary time origin. In some situations, it is desired to compare time stamps from two different devices. For example, in debugging and testing a System on Chip (SoC) device, external test equipment can be used to monitor events with respect to the System on Chip. The System on Chip can generate time stamps and associate them in a log with various events that occur internal to the System on Chip. Likewise, the external test equipment can generate its own time stamps and associate them in a log with various events that it detects in monitoring the System on Chip. It is often desired to correlate the logs to determine what events were occurring internal to the System on Chip at the time a certain external event was detected by the external test equipment. If the System on Chip and the external test equipment are on the same time domain, the time stamps of the different devices would be relative to the same time origin. However, if different time domains are used, the time stamps generated by the System on Chip and the external test equipment would be relative to different time origins, and, therefore, not correlated. Ad hoc comparison methods can be used to correlate the time stamps by checking for patterns of external activity.